Hair ethyl glucuronide as a biomarker of alcohol consumption in alcohol-dependent patients: Role of gender differences

BackgroundEthyl glucuronide (EtG) is a minor alcohol metabolite that accumulates in hair and is proposed as a stable marker for the detection of chronic and excessive alcohol consumption above a cut-off level of 30 pg/mg hair. A correlation between drinking behavior and EtG hair concentrations is observed, but large variability exists.AimsTo investigate the correlation between alcohol consumption and hair EtG concentrations in alcohol dependent patients, and the effect of gender differences as a factor for the variability on this correlation.MethodsEtG was measured by gas chromatography coupled to mass spectrometry in the hairs (first 3 cm) of 36 alcohol dependent patients (25 males/11 females) starting and alcohol detoxification program. Factors that possibly influence EtG content in hair (except age and gender) were excluded. Detailed retrospective alcohol consumption was obtained over the last 3 months using the Timeline Follow Back interview.ResultsMedian total alcohol consumption over 3 months was 13,050 g pure alcohol (range 60–650 g/day). Hair EtG concentrations varied between 32 and 662 pg/mg. There was a statistically significant linear and positive correlation between hair EtG and amounts of alcohol consumed (Pearson r = 0.83; p < 0.001), in both males (Pearson r = 0.83; p < 0.001) and females (Pearson r = 0.76; p = 0.007).ConclusionsThere is a linear correlation, with no significant effect of gender, between hair EtG concentrations and amounts of alcohol consumed in alcohol-dependent individuals. Analysis of EtG in hair can be applied to estimate retrospective alcohol consumption in both male and female alcohol dependent subjects using the same cut-off.